High noon in Libya

This week sees yet another crisis point in the Libyan case of six foreign health professionals sentenced to death on charges of injecting hundreds of children with HIV. Declan Butler traces the efforts of scientists to help establish the truth.

Rich Roberts did not realize what he was getting into last October, when he decided to mobilize his fellow Nobel laureates to draw attention to a death-penalty case in Libya. Six medical workers, five nurses from Bulgaria and a Palestinian doctor were charged with deliberately infecting more than 400 children with the virus that causes AIDS. Roberts, like many scientists, was shocked at how scientific evidence exonerating the medical workers had been ignored, and decided to do something about it.

For Roberts, a 1993 Nobel laureate in medicine or physiology, it was the start of a relentless commitment. Over the past nine months, he has had a string of meetings with top-level diplomats, and on 10 June he even flew to Libya for a late-night meeting at the Corinthian Hotel in Tripoli with Seif al-Islam Gaddafi, son of the Libyan leader Muammar al-Gaddafi, to try to help find a solution.

Roberts has also spent endless hours gathering an eventual 120 signatures from Nobel laureates, a record , for an open letter to Muammar al-Gaddafi. 'A miscarriage of justice will take place without proper consideration of scientific evidence', warned the letter (see Nature 444, 146; 2006). And it called on the appropriate authorities to take the necessary steps to permit such evidence to be used in this case.

On 31 October, just days before it was published, Roberts hand-delivered the letter to Libya ambassador to the United Nations, Attia Omar Mubarak. Their meeting in New York lasted an hour and a half. Mubarak was dismayed about the letter, arguing that the Islamic way was to try to negotiate a settlement between the accused and the injured. But, says Roberts, Mubarak did admit the possibility that the whole thing was an accident that had been seized on by prosecutors. As Nature went to press this week.

Meanwhile, a team of European experts in the molecular phylogenetics of viruses decided to apply their expertise to the HIV sequences of the infected children being treated in Europe. The initiative of the group, who until then knew little about the case apart from what they had read in the news, was to provide crucial new evidence.

The initial phylogenetic analyses of the sequences confirmed epidemiological evidence that the infection had started at the hospital before the medical workers had started working there. As the retrial drew to a close, the researchers worked night and day to finish their analyses, suspending all other uses of their 40-processor cluster supercomputer to dedicate it solely to analysis of the Libyan sequences.

Given the stakes, the team tested and retested their findings using multiple models. 'We decided to throw the book at the data', recalls Oliver Pybus, an evolutionary biologist at the University of Oxford, UK. The results of every model were concordant; the start of the outbreak predated the March 1998 arrival of the medical workers. The paper (- paper from de Oliveira T et al. Molecular epidemiology: HIV-1 and HCV sequences from Libyan outbreak) was published online in Nature on 6 December, just before the scheduled court verdict (see Nature 444, 836, 837; 2006).